[profiledata] Avoid creating a temporary vector in getNumValueData

[alexander-shaposhnikov]

Summary

getValueSitesForKind returns ArrayRef which has a cast operator to std::vector,
as a result a temporary is created if the type of the variable is const std::vector & .

Test plan: make check-all

[dblaikie]

Could you roll the expression into the range-for loop range expression? Naming the container doesn't seem to add much value.

[dblaikie]

Could you roll the expression into the range-for loop range expression? Naming the container doesn't seem to add much value.

[alexander-shaposhnikov]

address comments

[dblaikie]

Looks good - thanks!

llvm/trunk/include/llvm/ProfileData/InstrProf.h

uint32_t InstrProfRecord::getNumValueKinds() const {
   uint32_t NumValueKinds = 0;
   for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
     NumValueKinds += !(getValueSitesForKind(Kind).empty());
   return NumValueKinds;
 }
 
 uint32_t InstrProfRecord::getNumValueData(uint32_t ValueKind) const {
   uint32_t N = 0;
-  const std::vector<InstrProfValueSiteRecord> &SiteRecords =
-      getValueSitesForKind(ValueKind);
-  for (auto &SR : SiteRecords) {
+  for (auto &SR : getValueSitesForKind(ValueKind))
     N += SR.ValueData.size();
-  }
   return N;
 }
 
 uint32_t InstrProfRecord::getNumValueSites(uint32_t ValueKind) const {
   return getValueSitesForKind(ValueKind).size();
 }
 
 uint32_t InstrProfRecord::getNumValueDataForSite(uint32_t ValueKind,